Piezo stack actuators in flexible structures:
Experimental verification of a nonlinear modeling and identification approach
Piezoelectric actuators are applied in many mechatronic disciplines, from combustion engine injection systems to active structure vibration attenuation. This paper describes a nonlinear piezo stack actuator modeling and identification approach for flexible structure actuation. The piezo's inherent hysteresis behaviour is modeled by the widely applied Preisach model and is identified in the structure-mounted configuration using a frequency-averaging technique to mask out frequency-dependent structure response in the hysteresis identification. Moreover, linear structure identification, simulation, and experimental results are given. The experimental setup under study is a large-scale stack actuator, console-mounted on a steel truss with a low first natural frequency at about 20Hz. This system is used for model validation and to measure the performance of the system inversion, which can be seen as feed-forward control method. Feedback control can subsequently be supported and enhanced by eliminating the system nonlinear behaviour with the inverse hysteresis model, improving the control system's performance.